Numerous glycoproteins have been confirmed to screen AFP-negative liver cancer in clinical studies (44), including Golgi protein 73 (GP73) (45), dickkopf-1 (DKK1) (46), angiopoietin-like protein 2 (ANGPTL2) (47), and haptoglobin (Hp) (48). The gene discussed is DKK1; the disease is liver cancer.